Having a mobile QB is good. I think it's been proven, though, that QBs who run first, and recklessly, have short playing careers rife with missed games. See RGIII.
Kaep is a rare talent--great at both. I'd be surprised, though, that he plays a full season playing as he did this year. Luckily, he has a cannon arm and good decision making skills and great receiving talent and a great O line.
Pocket passers only work well when they A) have a great line, B) have deep talent to throw the ball to and C) a great running game.
Mobile QBs can play well with a deficiency in any of these.